WavSampleProvider: Fail initialization when channel_ids is incons…

…istent with the file.

PiperOrigin-RevId: 672592698

iamf/cli/tests/wav_sample_provider_test.cc

@@ -98,6 +98,22 @@ TEST(Initialize, FailsForUnknownLabels) {
       wav_sample_provider.Initialize(GetInputWavDir(), audio_elements).ok());
 }
 
+TEST(Initialize, FailsForChannelIdTooLarge) {
+  iamf_tools_cli_proto::UserMetadata user_metadata;
+  absl::flat_hash_map<DecodedUleb128, AudioElementWithData> audio_elements;
+  InitializeTestData(kSampleRate, user_metadata, audio_elements);
+  // Channel IDs are indexed from zero; a stereo wav file must not have a
+  // channel ID greater than 1.
+  constexpr auto kFirstChannelIndex = 0;
+  constexpr uint32_t kChannelIdTooLargeForStereoWavFile = 2;
+  user_metadata.mutable_audio_frame_metadata(0)->mutable_channel_ids()->Set(
+      kFirstChannelIndex, kChannelIdTooLargeForStereoWavFile);
+  WavSampleProvider wav_sample_provider(user_metadata.audio_frame_metadata());
+
+  EXPECT_FALSE(
+      wav_sample_provider.Initialize(GetInputWavDir(), audio_elements).ok());
+}
+
 TEST(WavSampleProviderTest, MismatchingChannelIdsAndLabels) {
   iamf_tools_cli_proto::UserMetadata user_metadata;
   absl::flat_hash_map<DecodedUleb128, AudioElementWithData> audio_elements;

iamf/cli/wav_sample_provider.cc

@@ -95,6 +95,18 @@ absl::Status WavSampleProvider::Initialize(
           " vs ", decoder_output_sample_rate, ")"));
     }
 
+    // To prevent indexing out of bounds after the `WavSampleProvider` is
+    // created, we ensure all user-specified channel IDs are in range of the
+    // number of channels in the input file.
+    for (const uint32_t channel_id : audio_frame_metadata.channel_ids()) {
+      if (channel_id >= wav_reader->num_channels()) {
+        return absl::InvalidArgumentError(
+            absl::StrCat("WAV (", wav_filename.string(),
+                         ") has num_channels= ", wav_reader->num_channels(),
+                         ". channel_id= ", channel_id, " is out of bounds."));
+      }
+    }
+
     wav_readers_.emplace(audio_element_id, std::move(*wav_reader));
   }